tailcoat

A tailcoat is a knee-length coat characterised by a rear section of the skirt (known as the tails), with the front of the skirt cut away.

The tailcoat shares its historical origins in clothes cut for convenient horse-riding in the Early Modern era. From the 18th century, however, tailcoats evolved into general forms of day and evening formal wear, in parallel to how the lounge suit succeeded the frock coat (19th century) and the justacorps (18th century).